(1) Field of the Invention
The present invention relates to a method and a device for controlling at least two subsystems of an aircraft. The invention relates in particular to the technical field of pilot interfaces for an aircraft of the rotorcraft type.
(2) Description of Related Art
A rotorcraft may be functionally subdivided into a plurality of subsystems. For example, a rotorcraft has subsystems relating respectively to flight controls, landing gear, a search light, cameras, a radio navigation system, a navigation system, an autopilot system, information display systems, etc.
A subsystem may include man-machine interfaces referred to more simply below as “interfaces”.
An “information interface” enables a pilot to receive information in visual, audible, or tactile manner.
A “control interface” enables a pilot to control members of the aircraft.
Furthermore, a subsystem may include an actuatable device capable of changing state on request, an actuator connected to an actuatable device in order to control the state of the actuatable device, or indeed measurement means for measuring at least one parameter.
An actuatable device thus represents a member of the aircraft that may be controlled on request, such as a search light, a winch, a camera, or indeed a movable airfoil surface, for example.
An actuator thus represents a member for operating such an actuatable device on receiving a command. An actuator may thus be in the form of a servo-control or of a switch, for example.
Furthermore, the aircraft may include a flight control subsystem.
The flight control subsystem includes actuatable devices that can be controlled in order to direct the aircraft. Such actuatable devices may comprise movable airfoil surfaces, wings, or blades of rotors, for example.
Furthermore, the flight control subsystem may include interfaces for controlling such control members. For example, a rotorcraft may include a cyclic control stick for controlling the cyclic pitch of the blades of a lift rotor by means of servo-controls, a collective pitch lever for controlling the collective pitch of the blades of a lift rotor by means of servo-controls, pedals for controlling a tail rotor for controlling yaw movement of the rotorcraft, and a throttle for controlling a power plant driving said rotors in rotation.
In addition, the aircraft may include a radio communication subsystem enabling a pilot to converse with third parties by using the interfaces of the subsystem.
The aircraft may also include a navigation subsystem for establishing a route to be followed, or indeed for displaying information relating to flight such as a heading being followed and the altitude of the aircraft, for example.
These interfaces are also used in an autopilot subsystem, e.g. for defining the mode of piloting to be applied.
Furthermore, display subsystems enable a pilot to monitor the operation of the aircraft. A subsystem of this type may comprise a fuel gauge, instruments for monitoring the power plant, or interfaces that display alarms in the event of a malfunction, for example.
This list of interfaces and subsystems is not exhaustive. Nevertheless, this list suffices to understand that a pilot may have a considerable workload while in flight.
In addition, modern aircraft can provide a pilot with the option of performing a wide range of missions. Some such missions are potentially complex and thereby increase the workload of a pilot. By way of illustration, a flight made through the middle of obstacles and/or with poor visibility is of a nature to complicate the work of the pilot.
Performing such missions may require multiple interfaces to be used, such as interfaces displaying obstacles that have been detected or that come from a database, or radars displaying weather conditions, for example.
Even though man-machine interface designers have made significant ergonomic progress, the overall workload on the pilot tends to increase on modern aircraft because of the increasing number of systems to be managed from the cockpit.
In the extreme, as from an excessive workload threshold, this workload can become dangerous because of the large number of actions that need to be performed.
In addition, a flight manual may specify that given actions should be implemented in a given sequence during particular stages of flight. A pilot must then commit those procedures to memory in order to carry them out in compliance with the predetermined sequence.
In particular, when the crew is faced with an unforeseen event, such as a failure, the crew must often respond quickly. The crew must therefore remember numerous procedures in order to be capable of reacting quickly.
Furthermore, such training can be difficult when the same crew flies several different aircraft having different procedures that all need to be remembered.
Furthermore, in the event of a failure, the aircraft may be in a situation that is stressful for the pilot. By way of example, a fuel leak can lead to considerable stress for the pilot. The pilot must then apply a predetermined procedure under a time constraint that is pressing. Under such circumstances, the pilot's workload can very quickly reach a level that is excessive and thus dangerous.
Furthermore, the interfaces of an aircraft are usually configured manually by the crew in a sequence of actions that the pilot is supposed to know. For example, when a search mission has terminated, the pilot reconfigures the interfaces so as to make available all of the information the pilot needs to return to a predefined base under the best possible conditions. Thus, the pilot requests various screens of the instrument panel to display in particular the route to be followed and associated weather information, together with information coming from a search radar. The pilot might possibly activate an autopilot system so that the aircraft follows a programmed route automatically.
If the pilot makes mistakes while performing these steps, those mistakes can become problematic. For example, the pilot ought to verify the pertinence of the route to be followed in the light of the quantity of fuel that remains in the tank of the aircraft. If the quantity of fuel is wrongly estimated, the aircraft might not be able to reach the intended destination.
Consequently, the workload on a pilot in flight is so great that performing certain complex missions requires the presence of an assistant (a pilot or some other person). Furthermore, the various crew members must coordinate their actions, and such coordination itself naturally implies additional workload.
Consequently, an aircraft has a plurality of man-machine interfaces made available to at least one pilot in order to perform missions of greater or lesser complexity. Nevertheless, using such man-machine interfaces can turn out to be difficult.
Document US 2013/0345920 describes an autonomous control system for a pilotless aircraft. That document is therefore remote from the field of the invention.
Likewise, Document WO 2012/161630 relates to a pilotless aircraft.
Document US 2011/160937 describes a centralized management method.
That method includes a step of creating tasks, a step of ordering tasks, and a step of executing tasks.
Document US 2010/161157 relates to a task management device.
Document US 2014/200747 describes a device for automatic management of configuration and reconfiguration of a plurality of systems of an aircraft.